The invention relates to blow molding machinery and more particularly to an apparatus for automatically removing flash from extrusion blow molded, plastic objects.
During the extrusion blow molding process, flash is often formed along a portion of the parting line of the molded object. For example, the bottom or base of the container may have a xe2x80x9ctailxe2x80x9d which is the result of clamping the plastic extruded between the two mold halves. There is also generally unwanted plastic flash attached to the top of the container adjacent to where the threads of the container are formed. If the container has a handle, the section between the handle and the container also contains a web of plastic material corresponding in thickness to two layers of the original parison.
Although there have been a number of different approaches taken to solve the problem of removing flash from extrusion blow molded plastic containers, each of the prior art approaches is complicated and costly. Also, if these prior art devices are not properly operated, the deflasher apparatus can damage the container and render it unacceptable.
These deflashing operations must be performed rapidly and reliably and the apparatus performing the operation must be compact and capable of handling containers at a rate equal to the rate at which the extrusion blow molding machine produces the containers. Also, transfer and trimming of the containers requires that the bottles be accurately oriented prior to deflashing to permit trimming without damage to the container sidewall or bottom. The deflashing apparatus must be compact to minimize factory floor space. None of the known prior art devices are able to meet all of the above requirements.
Therefore, there is a need for a compact apparatus that is preferably in-line with the blow molding machine so as to minimize floor space, and one that is capable of deflashing containers in one continuous motion at a rate equal to the rate at which the blow molding machine produces the containers.
The present invention is a novel rotary deflashing apparatus for plastic, blow molded articles. The deflashing apparatus is a dual rotary trimmer having two balanced, continuously counter-rotating wheels, namely a nest tool wheel and an intermeshing trim tool wheel. A screw advances the articles sequentially into engagement with the trimmer whereby the articles are deflashed of the tail, body, and the top flash when the nest tool is in juxtaposed position with the trim tool.
It is an object of the present invention to provide a trimmer that is simpler than prior art devices and is capable of deflashing articles of top flash, body flash, and tail flash at a rate equal to the rate at which the blow molding machine produces the articles.
It is another object of the present invention to provide a trimmer that is compact in size and continuous in operation to maximize throughput.
A still further object of the present invention is to provide a trimmer that picks up the article, removes all of the flash from the article and releases the deflashed article in one continuous motion.
These and other objects of the present invention will become apparent to one skilled in the art upon reading the following specification and by reference to the drawings.